(BioMed Central, 2017) Coleto, Inmaculada; Peña, Marlon de la; Rodríguez Escalante, Jon; Bejarano, Iraide; Glauser, Gaëtan; Aparicio Tejo, Pedro María; González Moro, María Begoña; Marino Bilbao, Daniel; Ciencias del Medio Natural; Natura Ingurunearen Zientziak
Background: The coordination between nitrogen (N) and sulfur (S) assimilation is required to suitably provide
plants with organic compounds essential for their development and growth. The N source induces the adaptation
of many metabolic processes in plants; however, there is scarce information about the influence that it may exert
on the functioning of S metabolism. The aim of this work was to provide an overview of N and S metabolism in
oilseed rape (Brassica napus) when exposed to different N sources. To do so, plants were grown in hydroponic
conditions with nitrate or ammonium as N source at two concentrations (0.5 and 1 mM).
Results: Metabolic changes mainly occurred in leaves, where ammonium caused the up-regulation of enzymes
involved in the primary assimilation of N and a general increase in the concentration of N-compounds (NH4
+, amino
acids and proteins). Similarly, the activity of key enzymes of primary S assimilation and the content of S-compounds
(glutathione and glucosinolates) were also higher in leaves of ammonium-fed plants. Interestingly, sulfate level was
lower in leaves of ammonium-fed plants, which was accompanied by the down-regulation of SULTR1 transporters
gene expression.
Conclusions: The results highlight the impact of the N source on different steps of N and S metabolism in oilseed
rape, notably inducing N and S assimilation in leaves, and put forward the potential of N source management to
modulate the synthesis of compounds with biotechnological interest, such as glucosinolates.
